ENGLAND Walker's towable propeller loch (or sillometers), model "Trident Ship-LogCherub rotators used", for fishing boats and cargo ships. Includes : - a brass, trickle-proof case, removable by engagement on a bracket fixed to the ship's aft gunwale. Graduated dial with scale from 0 to 100 nautical miles and 2 small central scales, one from 0 to 10 miles and the other from 0 to 500 miles. Signed "Walkers' & son" and marked "Trident". Tilt-opening glass window for manual hand reset. Manufacturer's plate on case. Case diameter: 13 cm. - two brass flywheels, Diameter: 25.3 cm - three metal olives and a brass spare holder. - one brass propeller. Length: 29.2 cm. = Some wear and tear.